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12 Threads found on Flyback tl431 Feedback
How to choose the optocoupler for feed back for a flyback converter. Is it necessary to use tl431 with optocoupler (As i have seen in almost all flyback power supply)
I would like in switching power supplies controlled TopSwitchJX (flyback) replaced the error amplifier with an external reference.Suggest you consult as compensation network, gain, etc.? Basically my point of replacement tl431, operational amplifier and a fixed reference point I used the DAC to control the output voltage of the source.
With the second scheme, you changed the flyback into a forward converter, not what you want, I guess. Twe too high output voltage in first case isn't a problem of transformer design, it means that the feedback circuit isn't working. Your schematic has a missing ground connection, but there may be other problems too. The tl431 circuit is (...)
hii, what would be the circuit and design parameters i need to consider if i have to design a feedback circuit using tl431 for a non isolated smps. Even though i am using a transformer. But the secondary and primary ground are common. 2. In a multiple output flyback smps, reflected voltage is secondary voltage multiplied by turns (...)
Hello, I do isolated , offline flyback. tl431/Opto-coupler feedback. The problem is, the 1K resistor that's across the opto-diode to provide the tl431 bias current, places a voltage across the opto-diode of 1 Volt.... ...this in turn makes it conduct current, which is a big big problem on maximum load, because if (...)
Hi, I'm building a voltage feedback flyback converter to turn a 12v input into a 24v output at 1Amp. I've successfully simulated and built this circuit on breadboard without isolation. Now I'm adding isolation. A tranformer in the forward path and an opto-coupler in the feedback path, but I'm having major headaches with the opto-coupler. (...)
Hi I am doing offline flyback with Vout = 36V and 22W. The following feedback scheme, using tl431 biased by a current source, appears to work fine on the simulator, and solves the problem of running too much current through a bias resistor to the tl431 during times of light load...... CIRCUIT DIAGRAM:-
Hello, I am doing an offline flyback with vout = 36V at 22W. (the PWM controller is to be NCP1217) This is how i initially intended to do the feedback circuit........... tl431 feedback CIRCUIT with bias resistor ...The tl431 is only rated up to 36V, so i need the 20V zener as in the above di
Where can I find more info on flyback converter feedback circuits. I am using TOP switch IC to design a flyback converter. But want to learn more about the feedback ckts used.
Hello, Basso?s book, page 290 gives the transfer function of the tl431/OPTO feedback network in a flyback converter as per the transfer function in the below diagram. *****Diagram and transfer function of OPTO / tl431 feedback question is, supposing that I don?t use the CLC filte
Hello, This circuit is in between output 36V_A and feedback optocoupler in flyback dc/dc converter. Could anyone help to explain what R813, R821, C819, C820, C822, C825, C821 R822 and C825 are meant for? Thanks, bittware
, I have designed a flyback smps for 4.2V/2A.using TNY268. Underno-load condition its working fine between 100V ac to 250V ac. but when i am giving .5A load the voltage dips to 2.9V, ie i am not able to achieve regulation. I have used 3.3V /.5W zener. biasing resistance for zener is 270r, and opto used is SFH6186. Wat could be the possi